This invention relates to magnetic tape cassettes. In particular, it relates to a small video cassette having a slide type brake member which is adapted to stop the rotation of the tape reels in the cassette.
A conventional brake member of this type is as shown in FIGS. 1, 2, and 3. FIG. 1 is a perspective view of the brake member. FIG. 2 is a sectional view of the brake member when the cassette is stored (or not in use). FIG. 3 is a sectional view of the brake member when the cassette is in use.
As shown in FIG. 2, a brake member 1 (FIG. 1) is arranged in alignment with a brake releasing lever insertion hole 2a in the lower half 2 of the cassette. The cassette has an upper half portion 2c. The brake member 1 is biased towards reels 5 by spring 3 so that each end portion 1a of the brake member 1 engages and locks the gear 5a of the respective reel 5. Since the end portions 1a are angularly disposed when they engage each gear 5a, the gears are locked. The magnetic tape cassette is constructed as described above. Therefore, when the cassette is not in use, the reels 5 cannot turn and accordingly, the tape is not slackened or unwound. When the cassette is used, a brake releasing bar 6, shown in FIG. 3, having a tapered insertion end is inserted into the brake member from the video deck, so that the brake member 1 is moved away from the reels 5 while sliding on the inner wall of the upper half of the cassette 2c. As a result, the reels 5 are unlocked.
As is apparent from the above description, in the conventional magnetic tape cassette, the brake releasing bar 6 is inserted into the brake member through the brake releasing bar insertion hole 2a of the lower half 2, so that the brake member 1 is slid while being pushed upwardly. However, sometimes the brake member 1 has play associated with it, or slides unsatisfactorily so that the braking member is not smoothly released. This drawback is significant especially in the case of a small video cassette because the above-described mechanism is smaller. If the brake member end piece 1a brakes or is bent, the locking function is lost, or the tape itself may be damaged.